1. Field of the Invention
The present invention relates to a manual paper-loading device for an electrostatic printer such as a copying machine, laser printer, etc. More particularly, the invention relates to a paper-loading device having a manual paper feeder for manually delivering irregular-sized paper into the electrostatic printer instead of delivering regular-sized papers in an ordinary automatic paper-loading tray.
2. Description of the Background Art
Generally, the electrostatic printer prints automatically and sequentially on regular-sized papers delivered from a paper-loading tray. However, it is sometimes necessary to manually supply an electrostatic printer with irregular-sized papers instead of regular-sized papers. FIGS. 2 and 3 illustrate two kinds of conventional apparatuses for manually delivering irregular-sized copying paper.
Referring to FIG. 2, the radii of a pickup roll 20 are not uniform, so that a gap is formed between the smallest radius of the pickup roll 20 and the paper placed on the uppermost part of the paper-loading tray 11. When putting irregular-sized paper into the gap, the pickup roll 20 causes the paper to enter into the printer by way of a pad 21. One of the drawbacks of the conventional apparatus is that manufacture of a pickup roll is very difficult because the pickup roll has nonuniform radii throughout the overall surface from the axis of the pickup roll. Moreover, when the pickup roll 20 is in a stand by status, additional mechanism is needed for adjusting the pickup roll 20. The adjustment is such that the circumferential portion of the pickup roll 20 with the shortest radius focus towards the paper-loading tray 11 so that the gap is formed between the pickup roll 20 and the paper placed on the uppermost portion of the paper-loading tray 11.
Referring to FIG. 3, additional pickup rolls 30 are provided over a pickup roll 25 for manually delivering paper. A paper sheet in the paper-loading tray 11 is delivered into the electrostatic printer by the pickup roll 25, while the irregular-sized papers are delivered one by one into the printer by the additional pick-up rolls 30 by way of a guide 31. One of the drawbacks of the conventional apparatus illustrated in FIG. 3 is that the two pick-up rolls 30 as well as the mechanisms for driving them must be supplied in addition to the standard pickup roll 25.